Are these dolphins having fun or being terrorized?

A YouTube video titled “Dana Point Dolphin Stampede,” showing perhaps 2,000 common dolphins in a frenetic charge alongside a Southern California whale-watching boat, made the rounds last week and is stirring emotions ranging from awe to dismay as it gets passed around on the Internet, GrindTV.com is reporting:

“I want to know why the boat didn’t stop instead of plowing through those dolphins? I wonder how many of them got hit,” reads a comment beneath a video report on the Weather Channel website.

A Discovery News report stated: “Contrary to the idea that the dolphins are having a grand ol’ time, it’s more likely that the noise, vibration and water turbulence caused by the boat may have frightened the dolphins, which all reacted at once. As one YouTube commenter asks: ‘Do you really have to drive your boat through the middle of them?’ “

We, frankly, don’t know what we’re looking at in that video. But we’ve seen a few seemingly playful dolphins ride alongside the ferries Galveston, and assumed they were having a good time:

Here are some porpoises riding alongside a boat in Puget Sound near Seattle:

Those dolphins in the California video seem to be in a frenzy, maybe because of the sheer number of them. But we wonder why they don’t just duck under the water and swim away? Couldn’t they outswim this meandering boat? Any dolphin behaviorists out there who can explain?